Quantum-state tomography of single-photon entangled states
| Autor: | C. Henelsmith, Mark Beck, Walker D. Larson, E. T. Burch |
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| Rok vydání: | 2015 |
| Předmět: | |
| Zdroj: | Physical Review A. 92 |
| ISSN: | 1094-1622 1050-2947 |
| DOI: | 10.1103/physreva.92.032328 |
| Popis: | We have performed quantum-state tomography on several different single-photon entangled states, that is, states in which a single photon is shared between two possible paths. We begin by doing a tomographic reconstruction of density matrices in the subspace where a single photon is shared by two spatial modes. In this subspace we are able to create high-fidelity, path-entangled states. Also within this subspace we use the Akaike information criterion and Monte Carlo simulations to help us estimate the amount and source of state drift in our system. We find that the primary state drift is due to phase drifts and fluctuations on the order of $\ensuremath{\pi}/400$ in our experimental apparatus. We then use the single-photon subspace density matrices and further measurements to estimate density matrices in the larger space consisting of two modes containing up to one photon each. In this larger space we find that the concurrence of the density matrices is $C\ensuremath{\cong}0.08$ and is greater than 0 by at least 45 standard deviations, indicating that our states are indeed entangled. |
| Databáze: | OpenAIRE |
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